The present invention relates to a gearhead assembly of a drive shaft and a output shaft, especially of a hedge trimmer attachment for a trimmer, in which the output shaft is arranged in a second housing part and is positioned laterally displaced to the drive shaft positioned in a first housing part. A central gear is positioned between the drive shaft and the output shaft and is secured on a bearing shaft extending perpendicularly to the drive shaft and the output shaft. The bearing shaft is positioned with one end in the first housing part and with the other end in the second housing part. The second housing part together with the output shaft is pivotable in a plane parallel to the drive shaft relative to the first housing part about the bearing shaft.
Such a gear head assembly is known from German Patent Application 41 16 885. The drive shaft is supported in a first housing part which is connectable to the free end of the guide tube of a trimmer. At the first housing part a second housing part is rotatably secured which houses the output shaft. A central gear wheel is provided in the housing between the drive shaft and the output shaft which is secured on a transversely extending bearing shaft secured with one end in the first housing part and with the other end in the second housing part. The bearing shaft intercepts at a right angle the imaginary axes of rotation of the drive shaft and the output shaft whereby the second housing part with the output shaft is pivotable relative to the first housing part about the bearing shaft in a plane which extends parallel to the drive shaft. For securing respective pivot positions, a catch device is provided between the first housing part and the second housing part. The catch device is embodied as a toothed catch curve which cooperates with a matching multi-tooth catch lever. One problem of such a catch device is that play usually results between the catch lever and the catch curve which may result in shaking and knocking of the tool resulting from the drive moments acting on the gearhead. Especially in the case of an adjustable gearhead (in connection with a hedge trimmer attachment) arranged at the lower end of a long guide tube of a trimmer such shaking movements resulting from the drive moments are very disruptive and prevent a fatigue-free, precise guiding of the tool.
It is therefore an object of the present invention to embody a gearhead assembly of the aforementioned kind such that without great constructive expenditure a substantially play-free locking of the adjustable housing parts to one another is possible.